package main

import "fmt"

func main() {
	score := 90
	var grade string
	switch {
	case score >= 90:
		grade = "A"
	case score >= 80 && score < 90:
		grade = "B"
	case score >= 70 && score < 80:
		grade = "C"
	default:
		grade = "D"
	}
	fmt.Println(grade)

	var a string = "daddy"
	switch a {
	case "mun", "daddy":
		fmt.Println("是的")

	}

}
